Stop-motion device



Sept. 20, 1932. ALLEN ET 1,878,091

STOP MOTION DEVICE Original- Filed April 24. 1928 5 Sheets-Sheet l 66m;M a ATTORNEY Sept. 20, 1932. E. B. ALLEN ET AL STOP MOTION DEVICEOriginal Filed April 24, 192? 5 Sheets-Sheet 2 INVENTOR figura flA/len/7/6110) {Myers A TORNEY Original Filed April 24, 1928 5 Sheets-Sheet 3I!lIlllllllllllllllllllllllllln...

N V E N TO R Ell/aid BAl/en/ i Walter Z@ers ATTQRN EY WITNESS Q Sept.20, 1932. E. B. ALLEN ET Al.

, STOP MOTION DEVICE 5 Sheets-Sheet 4 INVENTOR Zia/and flAl/en/ ATTORNEYOriginal Filed April 24. 1928 Sept. 20, 1932.

E. B. ALLEN ET AL STOP MOTION DEVICE 5 SheetS-Sheet 5 Original FiledApril 24, 1928 Eli. 1| ll ITNESS Patented Sept. 20, 1932 UNITED STATESPATENT 0mm I EDWARD B. ALLEN, OF NEWTOWN, AND WALTER.MYERS, 0FBRIDGEPORT, CONNECTI- CUT, ASSIGNORS TO THE SINGER. MANUFACTURINGCOMPANY, OF ELIZABETH, vNEW j JERSEY, A GORPGRATI ON OF NEW ERSEYSTOP-BIOTION DEVICE Application filed April 24, 1928, Serial No.272,416. Renewed September 11, 1931.

This invention relates to devices for stopping machines, such as sewingmachines, at a'predetermined'time and with the parts in a predeterminedposition.

One form of stop-motion device commonly used is shown in the patent toAllen, No.

743,213, of Nov. 3, 1903. 'It comprises a termined position. The shockof stopping the moving parts of the machine is borne by thebutter-spring means between the stopcam and the machine shaft. Thisshock is in the nature of a sharp hammer blow and is such that quite astrong buffer-spring is re,- quired to absorb it. Known stop-motions ofthis character area speed-limiting factor of machines to which they areapplied. In fact a machine with such a stop-motion must be operated at amoderate speed or considerable difliculty is experienced withbuffer-spring breakage and distortion or undue-wear on the parts. r

The present invention has for an object to provide a stop-motion device,which .will permit of higher machine speeds withincreased production,and in which the shock of stopping the machine is materially reduced andbufi'er-spring breakage is overcome. Another object of the inventionisto adapt the stop-motion device for use moreparticularly with buttonholesewing machines in which the power for operating the buttonhole cutteris derived from the momentum of the machine acting preferably throughthe stop-motion device after the machine is disconnected from itsdriving means;

a further object being to secure increased ower for operating thevbuttonhole cutter.

Still further, the invention has for an object to provide a stop-motiondevice in which usual stop-cam of the stop-motion devi'ce, 'in+ stead ofbeing mounted upon the driven shaft of the machine, is associatedpreferably with "an idly running gear meshing with afsmaller pinionfixed to the driven shaft, whereby the stop-cam is caused to run, say,at one-half the speed of the driven shaft. When applied to a buttonholesewing machine, this gear and stop-cam may conveniently be mounted on astud carried by the machine frame at one side of the main-shaft; theusual stop-motion lever being moved laterallyfrom its old position belowthe main-shaft, to its new position below the gear. Since the stop-camruns at half its former speed, it follows that the machine hastwice thetime to run under its own momentum from the time thejpower is thrownofl? until the positive stop comes into play, This increased coastingtime results in an absorption of energy by friction inthe machinebearings and a lessening of the energy to be absorbed by the stop-motionde- 1 vice. Furthermore, the character of the blow I imparted to thebuifer-spring means is changed. Instead of being in the nature of asudden or sharp hammer below, it is more like a push and can be betterabsorbed'by the buflier-sp'ring with less strain upon thelatter.

Still further, when applied to a buttonhole sewing machine of the typewhere the *but tonhole cutter is operated by the down-motionof thestop-plunger under the influence of the eccentric portionqof the usualstopcam, the two-to-one reduction gearing gives increased power forcutting the buttonhole, as may be desirable with heavymaterials or whencross-seams are encountered.

In the accompanying drawings, Fig. 1 is a side elevation of a buttonholesewing machine embodying theinvention. Fig. 2 is a bottom plan view ofthe machine. 3

Fig. 100

is a rear end elevation of the machine.

4 is a disassembled perspective view of the idly running gear andassociated parts, including the stop-cam. Fig. 5 is a top plan view ofthe upper parts of the machine carried by the bracket-arm. Fig. 6 is asection, on an enlarged scale, on the line 6-6, Fig. 1. Fig. 7 is asection on the line 7-7, 5. Fig. 8 is a section on the line 8-8, Fig. 5.Fig. 9 is a transverse vertical section through the machine bed andbracket-arm, showing the driving connections for the feed-wheel shuttlemechanism 8 to form the buttonhole stitches. The cutter-bar 6 has fixedto its lower end theusual buttonhole cutting knife 6 which, at the endof the sewing operation, is projected downwardly to cut the buttonholeslit.

The needle and shuttle mechanisms are driven in the usual manner fromthe mainshaft 9 which is ournaled within and lengthwise of thebracket-arm 3 and carries at its rearward end the tight and loosebelt-pulleys 10 and 11. The pulley 10 has an elongated hub 12 in whichgear-teeth are cut forming a pinion 13; the hub 12 being fixed to themainshaft 9 by means of the taper-pins 14 disposed on opposite sides ofthe pinion 13 and bearing a 90 angular relation to one another, as shownin Fig. 6. The loose pulley 11 is journaled on the bushing 15, Fig. 7,which is confined to rotate with the shaft 9 by means of the pin 16which enters a notch 17 in the bushing.

The sewing machine frame is formed at the bend of the bracket-arm,adjacent the upper end of the standard 2, with a boss 18 which islaterally offset from the rear main-shaft bearing 19 and has fixedthereto the stud-pin 20 on which is journaled the gear-wheel 21 meshingwith the pinion 13. As will be noted 'in Figs. 3 and 5, the stud-pin 20is parallel to the main-shaft 9 and is disposed substantially at thelevel of such main-shaft; being merely displaced to one side of thelatter. The gear-wheel 21 has a forwardly eXtending hub 22 on which isjournaled the usual stop-cam 23 having the eccentricstop-plunger-depressing portion 24 followed by the stop andrebound-preventing notch 25. Thestopcam 23 has fixed thereto a pin 26which eX- tends through a slot 27 in the face of the gear 21 and hasfitted thereon a block 28. The block 28 is disposed within the cavity29, Fig. 4, of the gear 21 and there is also fixed withwardly into thestop-notch 25.

The stop-motionlever 38 is heldinits run- Mounted on the standard 2, atthe base of the latter, is the bracket 35 having spaced arms 36 for thetrunnion-screws 37 which support the tilting stop-motion lever 38 formedat its upper end with a lateral arm 39 carrying the belt-shipper fork40. Mounted to slide verticallyin the stopanotion lever 38 is the usualstop-plunger 41' which is pressed upwardly by the spring 42. When thestop-motion lever 38 is in running or dotted line position, Fig. 1, theupper end of the plunger 41 is disposed forwardly of the cam 23 and isout of range of the latter.

When the stop-motion lever 38 assumes its stopping or full lineposition, Fig, 1, the plunger 41 is moved to a position under or withinrange of the cam 23, whereupon the eccentric portion 24 of such camfirst depresses the stop-motion plunger 41 against the force of thespring 42 and then releases the plunger as the latter rides off of theend of the eccentric portion 24 and is projected upning or dotted lineposition, Fig. 1, by means of a latch-lever43 -which enters the notch 44in the side of the rod 45 connected 'by the screw 46 to the arm 47 rigidwith thestopmotion lever 38. The latch 43 carries the adjustabletripping-point 48 which is acted upon-at the end of the sewing'cycle bythe tripping-point 49 carried by the feed-wheel 50; the feed-wheel beingconnected in the usual manner to move the work-clamp 50' on the bed 1 tofeed the work. 1

Fixed to the stop-motion plunger 41 by means of the screw 51 is thehorizontal bar 52 carrying at its outer end the roller 53 enterlever 55which is fulcrumed at 56 on the standard 2. The lever 55 is connected inthe usual manner to the cutter-bar 6 by means of the link 57,-lever 58and link 59. The link 57 has pivoted thereto at 60 the lower end i ofthe latch 61 having at its upper end a shoulder 62 which engages underthe pin 63' carried by the lever 58 and passes through the slotted-upper end of the link 57. This is the usual No. 743,213, for preventingthe operation of the cutter-bar by the stop-motion device; the releasebeing efiected by manually swinging the slot 54 in the rearward end ofthe l manual release, disclosed in said Allen patent ing the link 61 tocarry its shoulder 62 out from under the pin 63.

The feed-wheel 50 is mounted on the shaft 64 to the upper end of whichis fixeda gear 65 meshing with the pinion 66 fast to the gear 67 meshingwith the pinion 68 secured to the lower end of the shaft 69. The shaft69 has fixed thereto the usual star-wheel 7 0 which is given astep-by-step motion by the pins 71 carried by the bevel gear 72 whichmeshes with the driving pinion 73 fixed to the mainshaft 9.

It will be noted from the foregoing description that the power fordriving the machine is not transmitted through the gearing 13, 1,

' but is transmitted directly from the pulley 10 to the main-shaft 9;the gear 21 which carries the stop-cam 23 running idly without noise orwear and tear while the machine is in operation.

The tripping-point 48 should be adjusted to release the stop-motionlever38 at a time when the concentric or low portion of the stop-cam 28is adjacent the upper end of the plunger bar 41. On the cam 23 there isan angular space of about 90 where the tripping may take place andpermit the plungerbar 41 to pass under the cam for engagement by theeccentric cam-portion 24. As the cam 23 is geared to run at half thespeed of the main-shaft 9, it follows that the main-shaft may turnthrough a space of 180 or twice as far as would be permissible were thecam 23 mounted on the main-shaft. Hence it is not necessary to adjustthe setting of the tripping point 48 to the degree of accuracyheretofore required.

It is found that with the present stopmotion device lighterbuffer-springs may be used with increased machine speed and, due to themore gradual character of the blow absorbed by such buffer-springs,breakage of the latter is eliminated.-

Having thus set forth the nature of the invention, what we claim hereinis 1. In a stop-motion device, the combina tion with the driven machineshaft, driving means, and means for establishing and interruptingdriving relation between the driving means and driven shaft, of astop-cam geared to said driven shaft to run idly at a reduced speedwhile the machine is in operation, said stop-cam having an eccentricportion followed by a stop-notch, a stopmotion lever, and aspring-pressed plunger carried by said lever and movable into and out ofcooperative relation with said stopcam, and buttonhole cutting mechanismconnected tobe operated by the movement of said plunger under theinfluence of the cocentric portion of said stop-cam.

2. In a buttonhole sewing machine having a main-shaft, the combinationwith a stopmotion device including means geared to the main-shaft to runat a reduced speed and a stop-cam driven by said means, ofbutto-nholecutting mechanism connected to be operated by said means' 3. In abuttonhole sewing machine having a main-shaft, the combination with astopmotion device including a stop-cam geared to said main-shaft to runat a reduced speed, of buttonhole cutting mechanism connected to beoperated by said stop-cam.

4. In a buttonhole sewing machine, a main shaft, stitch-formingmechanism, rotary means driven by the main-shaft at a reduced speedduring a stitching operation, a stop motion device including means fordisconnecting the main-shaft from its source of power, and buttonholecutting mechanism connected to be operated by said rotary means undermomentum after the main-shaft has been disconnected from its source ofpower.

5. In a buttonhole sewing machine, a mainshaft, power-means, means forestablishing and interrupting driving relation between the main-shaftand said power-means, stitchforming mechanism, and buttonhole cuttingmechanism including a rotarybuttonholecutter-actuator connected to saidmain-shaft to run at a reduced speed and timed to actuate thebuttonhole-cutter while the machine is running under momentum.

6. A buttonhole sewing machine having, a main-shaft, stitch-formingmechanism, a work-clamp, means for relatively moving the stitch-formingmechanism and work-clamp during a sewing period, power-means, a.stopmotion device for disconnecting the mainshaft from the power-meansat the end of a sewing period, a buttonhole cutting mechanism and apower-multiplying gear-connection between said main-shaft and saidbuttonhole cutting mechanism for actuating the latter-under the momentumof the machine after the main-shaft has been disconnected from saidpower-means.

In testimony whereof, we have signed our names to this specification.

EDWARD B. ALLEN. WALTER MYERS.

